Chuck.



E. G. SGHMELZKOPF.

CHUCK.

APPLIUATIOH FILED AUG. 18, 1911.

- Patented May 7, 1912.

w n m; 72: :2:

UNITED STATES PATENT OFFICE.

EDWARD C. SGHMELZKOPF, OF MADISON, WISCONSIN, ASSIGNOR T0 GISI-IOLTMACHINE- COMPANY, OF MADISON, WISCONSIN, A CORPORATION OF WISCONSIN.

CHUCK.

Specification of Letters Patent.

Patented May 7, 1912.

To all whom it may concern Be it known that I, EDWARD C. SOHMELZ- KOPF,a citizen of the United States, residing at Madison, in the county ofDane and State of Wisconsin, have invented certain new and usefulImprovements in Chucks, of which the following is a specification.

This invention relates to improvements in lathe chucks, the same beingin part applicable to the face-plate jaws of boring mills; and theinvention consists mainly in a novel end thrustbearing for the feedscrews of the aws, which shall afford an in creased amount of endbearing as compared with that found in the usual chucks of'this type;which shall be self-centering; which shall facilitate the machining ofthe ends of the slot or chamber which receive the end thrust-bearings;which are interchange able; which are easily and simply made from around rod; and which permit the easy removal of the bearings and screwfor; cleaning.

The invention will be readily understood from the illustration shown inthe accompanying drawings, in which- Figure 1 is a vertical sectionthrough a portion of the chuck substantially in the plane of the medianradial line of one of the slots of the sliding jaws, the jaw itselfappearing in elevation. Fig. 2 is a front plan view of the portion ofthe chuck shown in Fig. 1, with the jaw removed. Figs. 3, 4, and 5 aredetail views of the end thrust bearings. Fig. 6 is a detail elevation ofa dust-excluding plug forming one feature of the invention.

Referring to the drawings, 6 designates the chuck-body of the usualconstruction, having the central axial opening 7 for the spindle, andthe radial undercut slots 8 each adapted to receive a aw-base 9 to whichlatter is adjustably secured the jaw 10 by a clamping gib 10 and screws10", all as usual in chucks of this type.

The chuck-body 6 is cast with a chamber 11 in the bottom of the slot 8to receive the body portion of the adjusting screw 12. In accordancewith my invention the end portions of the chamber 11 are milled or boredto present approximately semi-circular seats 11 for the end-thrustbearings 13 which are seated therein; these seats, as best shown in Fig.2, having approximately semi-circular outer walls 11 constitutingabutments for the approximately semi-circular outer walls of thebearings 13. Beyond the outer seat 11 is a semi-circular slot 11 inwhich rests the neck 14 of the screw 12, the latter having the usualsquared end 15 forming a wrench-hold for the chuck-wrench. On the underside of the jaw-base 9 is a detachable half nut 16, preferably made ofhardened metal, and engaging the screw 12.

The end thrust of the screw 12 in either direction is taken by thebearings 13 which, as shown, are each formed with an outer substantiallysemi-cylindric face 13 engaging the wall 11 of the bearing seat 11 andan inner flat face 13 that is engaged by the end of the body of thescrew. Each bearing is also formed with a hole 13 through which the neck14: of the screw passes. These end bearings may be made from a round barof steel, in the following manner. A piece is first cut off of a lengthcorresponding to the height of the bearing to be formed.

This piece is then suitably chucked or held in a jig; and is sawedlengthwise in two pieces forming the inner flat face 13; this flat faceis then milled true to the semi-cylindrical face 13 The top or end isthen milled to form the substantially semi-circular top portion 13 andlastly the whole is bored being held in a jig to form the bearings 13for the neck portions 14L of the screw.

From the foregoing it will be seen that not only do the bearings 13afford bearings for substantially the entire surfaces of the ends of thescrew-body 12, and are self-centering or self-alining with relation tothe necks of the screw, but they are easily and cheaply made from aplain round bar of steel; and the substantially semi-circular orsemi-cylindrical form of their outer walls facilitates and cheapens themanufacture of the chuck-body especially with reference to the formationof the end thrust bearing seats 11*, which latter, as above stated, canbe very easily and cheaply machined. The jaw and jaw base can be removedby simply applying a wrench to the squared end 15 of the screw andscrewing the jaw base out from the outer end of its channel, or the jawalone can be removed from the jaw base by removing the screws 10 whichconnect it to the clamping gib. When the chuck jaw and base have thusbeen removed, by applying the wrench to the squared end 15 of the screwthe latter and the two end thrust bearings can be bodily lifted fromtheir seats.

Another feature of the invention resides in the provision, at the innerend of the base of the slot 12, of a dust-excluding plug 17, this lattercomprising a head 17 of substantially semi-cylindrical form adapted toslidably fit the concave inner surface of the jaw-base 9, and a shank orstem 17 which engages a socket 18 formed in the base of the slot 8, toreceive said shank or stem. This plug 17, formed and located asdescribed, prevents dirt from working into the threads on the screw 12and half nut 16, thereby making the jaw practically dust-- proof.

Although I have shown and described my invention as applied to the chuckof a lathe, it will be understood that the same is applicable to equaladvantage to the independent face-plate jaws of a boring mill, since thejaw and jaw-adjusting mechanism of such jaws is substantially like thatof a four-jaw independent chuck, and is subject to substantially thesame wear and other influences.

I claim 1. The combination with a chuck-body formed with a chamber toreceive the adjusting screw of the chuckjaw, said chamber having roundedconcave end walls, of an adjusting screw in said chamber having a bodyportion and reduced end or neck portions, and end-thrust bearings forsaid adjusting screw formed with flat inner faces engaging the ends ofthe screw-body and rounded convex outer faces engaging the roundedconcave end walls of the screw chamber, substantially as described.

2. The combination with a chuck-body formed wit-h achamber to receivethe adj usting screw of the chuck-jaw, said chamber having roundedconcave end Walls, of an adjusting screw in said chamber having a bodyport-ion and reduced end or neck portions, and end-thrust bearings forsaid adjusting screw formed with flat inner faces engaging the ends ofthe screw-body, rounded convex outer faces engaging the rounded concaveend walls of the chamber, and transverse apertures receiving and formingbearings for the neck portions of the screw, substantially as described.

3. The combination with a chuck-body having a guide slot for thechuck-jaw, of a chuck-jaw slidably mounted in said slot, and adust-excluding plug mounted on the inner end of the base of the slot andengaging the inner side of the chuck-jaw, substantially as described.

4;. The combination with a chuck-body having a guide slot for thechuck-jaw, the inner end of the base of said slot being pro vided with asocket, of a chuck-jaw slidably mounted in said slot, and adust-excluding plug having a stem or shank portion fitted to said socketand a head portion engaging the inner side of the chuck-jaw,substantially as described.

EDWARD C. SCHMELZKOPF.

Witnesses:

M. E. GoEoKs, W. L. MILLER.

. Copies of this patent may be obtained for five cents each, byaddressing the Commissioner of Patents.

Washington, D. C.

